Re: huffmandict: Matlab compatibility, Matlab bugs..

[Simon Persson]

On Thursday 05 October 2006 21:59, Muthiah Annamalai wrote:
> Hi there,
> Im trying to write some functions in Matlab communication toolbox
> (source coding functions) for Octave forge.
>
> While I was doing that, I came across a funny bug in Matlab.
>
> Huffman encoding is done in 2 steps (according to Matlab),
> and the first step generates dictionary.
> Essentially all Huffman coding does it map low probability symbols
> to long codewords and vice-verca.
>
>  So the wierd thing (in Matlab impl) is that for 0-probability symbols
> have long code words assigned to them. I wonder... why someone will
> infact even have a zero probability symbols occur in their data?
>

Maybe someone wants to estimate probabilites from a smaller sample than the 
full data to be encoded. Then codes for all symbols are still needed even if 
they don't occur in the analysed sample. That's the only reason I can think 
of.

Simon

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